1. Field of the Invention
The present invention relates to a pipe fitting wireform for field or shop application for measuring the center-to-end or end-to-center of a fitting to determine the end-to-end length of a pipe needed to connect a pair of pipe fittings in a pipe assembly.
2. Brief Description of the Prior Art
Dimensions on pipe drawings specify the center lines and/or points on center lines; they do not specify pipe lengths. This system of distance dimensioning and measurement is also followed in the fabrication and installation of pipe assemblies.
To determine actual pipe length, allowances must be made for the length of the fittings and the distance the pipe-to-be-cut will be threaded into the fitting. The method of doing this is to subtract an amount called the take-out from the center-to-center dimension. The relationships of the take-out to other threaded pipe connection distances, termed make-up, center-to-center and end-to-end are illustrated in FIG. 5. To determine end-to-end pipe length, the take-out is subtracted from the center-to-center dimension. Standard tables as shown in FIG. 5 may be used for this purpose.
Particularly in field installations, it is difficult for a man working by himself to make the center-to-end or end-to-center measurement between the fittings on the pipes to be joined. In addition, the standard tables used to determine the take-out must be used with judgment since commercially available fittings may vary by one turn or more plus or minus. Hence on critical connections, materials should be checked and compensation made for variances in the fittings.
In view of the above, it would be desirable to have a pipe fitting wireform that makes it easier for a man working by himself to make the center-to-end or end-to-center measurement and which may be used to compensate for variances in at least one of the fittings to be joined.